The invention relates to a tool for removing fastening members, in particular to a tool for removing nuts and studs.
Conventionally, nuts or studs would be removed by moving a spanner or a wrench which acts upon the side face of the nut or stud to cause its rotation. However, where the nut or stud has become damaged by its edges having become xe2x80x9croundedxe2x80x9d, it may be difficult to remove using the normal tools available. Also, in cases where nuts for instance have become seized, removal is problematic.
Existing methods for removing seized or damaged fastening members in such conditions involve drilling, burning or cutting the fastening member in question from the object to which they are attached.
Another problem which is often encountered concerns situations in which locking nuts have been used, but the specialized tool for unlocking of the nuts is not available.
In a common field of application, vehicles with alloy wheels utilize locking wheel nuts to prevent their theft. However, often the vehicle owner will not have the key or tool available in the event of a breakdown, for instance, after sustaining a flat tyre. Breakdown engineers called out to the scene often have very little option other than to tow the vehicle to a garage where further attempts would be made to remove the vehicle wheel in question. However, attempts at removal without the proper key or tool (which may well be for all practical purposes unique to the particular vehicle on which the alloy wheels are fitted) often result in damage to the wheel and add considerable time and expense to the repairs.
It will be appreciated that in the case of locking wheel nuts and in the case of seized or damaged fastening members in other situations, it may be only the end face of the particular fastening member which is accessible so that getting a good grip around the circumference of the fastening member is not a viable option.
In such cases, being able to only access the end face exacerbates the problem. Indeed, in the case of locking wheel nuts in particular there is often an outer shell which is arranged to be freely rotating with respect to a concealed and protected member underneath and in those cases attacking the outer shell using hammer and chisel etc or attempting to drill into the wheel nuts often results in the chisel face or the drill bit skating across the locking wheel nut and damaging the valuable alloy wheels.
It is an aim of preferred embodiments of the present invention to provide a tool for aiding the removal of fastening members which avoids, or alleviates to at least some extent, at least one of the problems described above in relation to the prior art.
According to a first aspect of the invention, there is provided a tool for aiding the removal of a fastening member from a structure to which it is attached by means of a threaded connection, the tool comprising: an elongate body member having first and second ends, the first end having means for deforming an end face of the fastening member to provide an area of purchase thereon; and
means to cause rotation of the fastening member to unscrew the fastening member from the structure.
The fastening member may comprise a nut or stud.
Preferably, said means to cause rotation comprise attachment means for the attachment of an operating member. The attachment means is preferably located at the second end of the body member.
The attachment means may comprise a standard connection, such as a half inch square drive in the form or a male or female connection. Other standard or specialised connections may alternatively be employed of course.
The operating member may comprise an impact means such as an impact driver for both imparting a blow to the tool and providing the means for rotation. An impact driver may be provided with the tool as an integrated package.
It is also within the scope of the invention that a first operating member may be linked to the tool by way of the attachment means in a first step so as to provide an impact to the tool, and a second, different operating member may be connected to the attachment means during a second step for providing said rotation. The first operating means may comprise a bar or similar for receiving a blow from a hammer, and the second operating member may comprise, for instance, a wheel brace.
The means for deforming the fastening member may comprise at least one cutting means such as a blade or a blade ring having blades arranged around an aperture formed in the blade ring for biting into said end face. The blade may be demountably attached to the elongate body. The blade may include an angled cutting edge. The tool may include means for securing the blade to the elongate body, such as by grub screws. The blade may be handed, so as to be orientable in a first configuration for use with fastening members having a right hand threaded attachment, and to be orientable in a second configuration for use with fastening members having a left-handed threaded attachment.
The first end of the body member may be provided with an aperture running longitudinally through the centre of the body member. The aperture may run part way through the body member or it may run entirely through the body member. The aperture may couple with the attachment means of the second end. The first end may comprise, in such a way that it forms the attachment means, at least one blade. Preferably two blades, are provided on either side of the aperture. The aperture may enable a bolt or similar object, on which is threaded a fastening member, to be lowered into the body member such that the blades come into contact with an end face of said fastening member.
When situated within the body member, the bolt may form part of the attachment means.
It is another aim of certain embodiments to include some means for locating the first end of the body member with respect to the end face of the fastening member.
With a view to fulfilling the above aim, the tool is preferably provided with locating means to locate the first end with respect to the end face of the fastening member.
The locating means may comprise centralising means.
The locating means may comprise a mandrel for engagement with the end face of the fastening member.
The mandrel may be spring mounted within the body member.
The mandrel may be of male or female type.
Preferably the leading end of the mandrel is tapered.
According to another preferred feature of the invention, the tool is provided with means for preventing peripheral damage to the structure.
For example a cover or shroud may be provided to surround the means for deforming the end face of the fastening member.
According to a second aspect of the invention, there is provided a method for facilitating the removal of a fastening member from a structure to which it is attached by means of a threaded connection, the method comprising:
deforming an exposed end face of the fastening member to provide an area of purchase thereon; and
rotating the fastening member using said area of purchase.
The method of the second aspect may include any one or more of the limiting features of the apparatus of the first aspect in any combination. The method may include the preliminary step of locating a first end of the tool with respect to the end face of the fastening member. This locating step preferably includes the use of the locating means.